split-mouth RCT, 25 months follow up. GBR protocol with LPRF as grafting material in the test group and autogenous bone with DBBM as grafting material in the control group.

6 patients were included in this split-mouth RCT. In control sites a horizontal GBR procedure was performed using a titanium reinforced dPTFE membrane with a graft consisting of 50% autogenous bone and 50% DBBM. In test sites a titanium reinforced dPTFE membrane was used, with a graft consisting of an LPRF block. This was left to heal for 9 months. Subsequently an implant was placed. At time of implant placement a bone biopsy was taken. After 4 months of osseointegration the abutment connection was performed. 1 year after loading of the implants a final check was done. CBCT scans were taken at intake, immediately after reconstruction, 9 months after reconstruction, before implant placement and 1 year after loading of the implants.

Primary outcome measure is the bone volume as measured on the CBCT scans. Secondary outcome measures are bone quality in the biopsy, buccal bone thickness around the oral implant, number and type of complications, cumulative survival rates of the implants 1 year after loading.

Inclusion Criteria:

• Males or females, with ASA I or II, between 18 and 80 years old
• 2 implant sites requiring vertical bone augmentation prior to implant placement
• Both sites in the same jaw
• Good general health as documented by self-assessment

Exclusion Criteria:

• Any systemic medical condition that could interfere with the surgical procedure, planned treatment or healing of the patient
• Immunosuppression, Diabetes, Anticoagulation or Antiaggregatory medication.
• Current pregnancy or breast feeding/ lactating at the time of recruitment.
• Radiotherapy or Chemotherapy in head and neck area.
• Intravenous and oral bisphosphonate therapy.
• Smoking
• Unwillingness to return for the follow-up examination.
• Conditions or circumstances, in the opinion of the investigator, which could represent a general contra-indication for surgical procedure or would prevent completion of study participation or interfere with analysis of study results, such as history of non-compliance, or unrealistic expectations
• Presence of osseous pathologies, that might interfere with normal wound healing
• Presence of oral lesions (such as ulceration, malignancy)
• Local inflammation, including untreated periodontitis
• Patients with inadequate oral hygiene or unmotivated for adequate home care

all info available on request

neither the patient, nor the outcome assessor was aware at which side which grafting material was used